It is known that Varroa jacobsoni is a mite parasitically living on Apis mellifera and which usually sucks at the faeces of bee-grubs by its sucking mandible and the pellicle of the pupae; but most willingly, it taps the haemolymph of the growing bees. As a result of the infection and in proportion thereto various distortioned evolution forms appear, the bees become weakened, become susceptible to other diseases and finally they perish.
The infection spreads to all important melliferious areas causing substantial losses. After the first infection, such losses appear in a surge-like manner, at the beginning in every third and fourth year and later in every second or third year. The death of the bee colony resembles an intoxication in most cases.
Several ways of protection against varroatosis are known:
1) Treatment or fumigation, respectively of the bee hives with various ethereal oils;
2) Application of various synthetic organic active agents, e.g.:
a synergistic combination of pyrethrin with piperonylbutoxide [see in: Chemical Abstracts World Patent Index (hereinafter: WPI) Acc. No. 86-212705/337; PA1 a combination containing tetradifon [the Pesticide Manual 8th Ed., the British Crop Protection Council, Registry Number (hereinafter: Reg. No.) 116-29-07 and dicofol (Reg. No. 115-32-2) (WPI Acc. No. 86-037330/06); PA1 bee wax containing an antiparasitic active agent, e.g. isopropyl 4,4'-dibromo-benzylate (WPI Acc. No. 85-290439/47); PA1 1-pyridylformimino-2-phenoxymethyl-2-imidazoline derivatives (WPI Acc. No. 85-224091/37); PA1 2-anilinomethyl-2-imidazoline derivatives (WPI Acc. No. 85-217891/36); PA1 2-dimethylphenylimino-3-methylthiazoline (WPI Acc. No. 84-284115/46); PA1 compositions containing azoxybenzene (WPI Acc. No. 82-95526E/45); PA1 acetone solution of an aryl N-methylcarbamate (WPI Acc. No. 78-82396A/46); and PA1 foods and drinking water containing synthetic pyrethroids (WPI Acc. No. 87.130028/19). PA1 WPI Acc. No. 87-129545/19 and PA1 WPI Acc. No. 84-018266/04; PA1 mechanical protection (WPI Acc. No. 84-302720/49) and PA1 sterilization of the mites by X rays (WPI Acc. No. 86-048673/08). PA1 the fermentation broth or cell-free fermentation broth, or PA1 a concentrate of the fermentation broth or cell-free fermentation broth, or PA1 a solidified form of the fermentation broth or cell-free fermentation broth of one or two bacterium strains deposited at the National Collection of Agricultural and Industrial Microorganisms, Budapest, Hungary under the identification Nos. 001083 and 001086 or of their mixed micropopulation, if desired, in a sterilized state, optionally together with the metabolism products arising during the fermentation and inutilized nutriments, as well as one or more solid and/or liquid carrier(s) (preferably sugar or a grist of natural minerals), or an inert solvent (e.g. water) and, if desired, with surface active (preferably anionic or nonionic emulsifying or dispersing) agents.
Compositions containing synthetic organic active ingredients are applied by dusting (atomizing) or fumigation on the hives. Such commercialized compositions (which have, however, not been authorized in all countries) are e.g. Mitac EC (200 g/l) and Mitac WP (250-500 g/kg) containing amitrase as active ingredient; and Ectodex EC (50 g/l) (The Pesticide Manual 8th Ed., 1987; The British Crop. Protection Council, entry number 330). Their use is possible only at an appropriate external temperature (above 10.degree. C.).
According to some suppositions, in the case of treatments carried out at the wrong time or with too high a frequency, damaging side products can be accumulated in the honey which may be harmful to both the bee-keeper and the honey as well.
3) Use of attracting and repelling agents (attractants and repellents):
4) Other methods of protection, e.g.